Derby Talk

Derby Talk is a forum for Pinewood Derby, Awana Grand Prix, Kub Kar Rally, Shape N Race Derby, Space Derby, Raingutter Regatta and other similar races where a child and an adult work together to create a race vehicle and a lot of fun and memories

How feasible do you think it would be to have the BSA wheels cast so that there is a bead or lettering on the /inside/ of the tread?

It seems like the most common scout rules mandate that you can "lightly sand" the outside of the wheel to remove imperfections, but you can't remove material from the inside of the tread to lighten it.

The problem is that there's no simple way for inspectors to tell what's been done to the inside of the wheel. On the outside, you can check the beading and lettering, but there's nothing on the inside.

So what if there were some kind of pattern or lettering cast into the inside of the wheel that would clearly be visible if lathed away? Would this be a reasonable thing to add? Would it be useful? What do you guys think?

I've always felt it was very difficult to check for such material removal during inspection. We use inspection gauges, but those only catch mods that impact the diameter of the wheel or its width. Removing material on the inside of the wheel can only be inspected visually and even then it can get difficult. I think anything that aides in that inspection process would be beneficial.

I also think it is difficult to inspect for oil use instead of graphite. We just hope folks obey that rule as I don't know of any good way to inspect for it.

As long as we are on the topic of hard to inspect rules, use of axles that come in the kit are another area that I find very difficult to inspect.

birddog wrote:I've always felt it was very difficult to check for such material removal during inspection. We use inspection gauges, but those only catch mods that impact the diameter of the wheel or its width. Removing material on the inside of the wheel can only be inspected visually and even then it can get difficult. I think anything that aides in that inspection process would be beneficial.

I also think it is difficult to inspect for oil use instead of graphite. We just hope folks obey that rule as I don't know of any good way to inspect for it.

As long as we are on the topic of hard to inspect rules, use of axles that come in the kit are another area that I find very difficult to inspect.

Somebody who knows what to look for can probably peg a wheel that's had material removed from the inside. However, then you have to deal with a bullheaded person claiming that they haven't done anything. Also, it's hard to train folks unfamiliar with the process to look for lathe marks. If there were some kind of raised marking on the inner tread, it would be an easy catch...either it's there, or it isn't.

For oil, I've heard that the standard test is to push a piece of paper or similar material into the wheel/axle gap and see if anything wicks onto it. Ideally you'd want something stiff, thin and not likely to shed fibers into the axle gap.

That is an excellent suggestion! Molding process would limit geometry, but, for example, shallow grooves across the now smooth portions of the interior could be molded. The critical geometry is that the grooves be inline with the exit motion of the mold. (I'm assuming that the interior mold does not twist as it is withdrawn.)

We solve the "inspect for oil" problem by allowing (and providing at our workshops) liquid lubricants.

I've heard of derbies using a "tip of axle must be visible" rule to facilitate checking for standard axles. That doesn't catch professionally machined standard axles, of course. But it does catch some non-standard axles.

And as Stan indicated, any markings on the inside of the wheel will need to take into account the way the wheel is released from the mold.

knotthed wrote:To heck with the next iteration of the wheel.............................

Let's talk about the next iteration of the axle where it doesn't have giant flashing underneath the head!!!!!

That would be a much better improvement to the kit than modifying the wheels in my opinion.

If the BSA would just follow the lead of the Awana kits and adopt the pins that they use, I think it would be so much better. Not only would they be straighter and cleaner, but there would be less reason to buy aftermarket axles in order to reduce the slop in the bores.

Back to the topic of adding tamper-marks to the inside of BSA wheels...does anybody know how I might get the ear of whoever is in charge of such decisions within the BSA? Would be nice to at least send them a proposal.

Vitamin K wrote:Back to the topic of adding tamper-marks to the inside of BSA wheels...does anybody know how I might get the ear of whoever is in charge of such decisions within the BSA? Would be nice to at least send them a proposal.

I think it is not necessary. What is necessary is education of the inspectors. I suspect anyone on this forum can identify an illegal wheel. Once you remove that outer step a Red Flag goes up. The nail head goes into the wheel much deeper than if it were not removed. The inside of a 1.8 gram wheel is obvious with the material removed and the edge it leaves even though the rim looks stock. A caliper and a GO/NO GO gauge will quickly identify an illegal wheel. The only wheel you can buy that cannot be detected would be Derby Evolutions "Revolution BASX" that was made round and will probably weigh 2.4 grams (also available from other vendors) . Any marking you put inside the wheel would not be affected. Is there a wheel anyone has in mind that a person can make or buy from a vendor where an illegal modification cannot be detected?
Back to the education of inspectors. A young lady was put in charge of our Districts inspection this year. Length, width, height, weight. That was it. We used a skin of the American flag from Maximum Velocity to cover the car. The young lady said, "Oh, look how pretty that is". There could have been any wheels and axles on that car and everyone watching the inspections knew the cars weren't being inspected thoroughly. Same thing in another District we raced. Boy Scouts were measuring the cars. If it fit the box it passed. Fortunately most people are honest.

I am all for training inspectors better. The problem is that most Derbies are volunteer operations that are far too short on manpower and time. A lot of stuff can fall through cracks, and I've seen inspection get hurried along for the sake of getting the race run. I don't like it, but it's always a struggle.

Even for the Mid-America, when I asked why they had such loose guidelines for wheels, I was told that due to the volume of cars to be inspected, they selected the criteria that could be quickly and objectively determined: Flat tread, bead on wheels, all lettering present. An interior marking would give another criteria that could quickly and objectively be pinpointed.

tl;dr: Training inspectors is best, but anything to make easier and faster the process of identifying wheel modification would be beneficial.

You could put several indents/grooves on the inside of the wheel that go across the width as I believe Sporty was suggesting, but putting lettering on the inside or a grooved ring would trap the steel on the part. You could get around some of that with something like a collapsible core, but that would increase the cost of the mold dramatically and the wheel sell price would probably increase as a result.